The browntail moth caterpillar population in Maine is down from its peak, but some areas are still seeing high numbers.
Allison Kanoti, the director of forest health and monitoring with the Maine Forest Service, said the population has declined in Androscoggin County, but grown in Penobscot, Knox, Waldo, and Hancock Counties, and in the area around Casco Bay.
"Since this outbreak started to build, and it really started to build in 2010, is that you get these pockets that are kind of squashed down by disease, but the population is able to bubble up in other places that are not as prevalent," she said.
Kanoti said the state measures the population by acres of defoliation.
"Going back to the mid-1990s, there wasn't a year in that stretch between 1994 and this year where we didn't map at least 400 acres of damage," she said. "So there's always some parts of the state that are experiencing those higher populations, even when the moth is not in an outbreak status."
Kanoti said the population peaked two years ago, when the state recorded 250,000 acres of defoliation. Last year it dropped to 47,000 acres, but she said the true number was likely higher because aerial surveys were hampered by rain.
Hairs from the browntail moth caterpillar are toxic to humans and can cause sever skin rash and breathing difficulties.
